Modulation of transport properties via S/Br substitution: solvothermal synthesis, crystal structure, and transport properties of Bi 13 S 17 Br 3
Modulation of transport properties via S/Br substitution: solvothermal synthesis, crystal structure, and transport properties of Bi 13 S 17 Br 3
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通过 S/Br 取代调节传输特性：Bi 13 S 17 Br 3 的溶剂热合成、晶体结构和传输特性
DOI：
10.1039/d2dt02295h
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发表时间：
2022
影响因子：
4
通讯作者：
Kovnir, Kirill
中科院分区：
文献类型：
--
作者：
Amarasinghe, Dinesh K.;Yox, Philip;Viswanathan, Gayatri;Adeyemi, Adedoyin N.;Kovnir, Kirill
通过对铋-S-卤素相空间的溶剂热合成探索，合成了两种具有共同结构基元的卤化铋化合物。Bi13S18I2被证实具有先前报道的组成和晶体结构。相反，与以前的报告相反，溴化物类似物被证明既没有Bi19S27Br3也没有Bi13S18Br2。经单晶X射线衍射法提纯并经元素分析、高分辨粉末X射线衍射法和全散射确证，由于骨架中的S/溴部分取代，其组成接近于Bi13S17Br3。Bi13S18I2和Bi13S17Br3是n型半导体，其光学带隙相似于∼0.9 eV，但电荷和热输运性质不同。由于骨架的S/溴无序，Bi13S17Br3表现出比含碘类似物更低的热导率和电导性。较高的Seebeck系数和极低的热导率表明，已报道的卤化铋是开发新型热电材料的良好平台。
The solvothermal synthetic exploration of the Bi–S–halogen phase space resulted in the synthesis of two bismuth sulfohalides with common structural motifs. Bi13S18I2 was confirmed to have the previously reported composition and crystal structure. In contrast, the bromide analogue was shown to have a formula of neither Bi19S27Br3 nor Bi13S18Br2, in contrast to the previous reports. The composition, refined from single crystal X-ray diffraction and confirmed by elemental analysis, high-resolution powder X-ray diffraction, and total scattering, is close to Bi13S17Br3 due to the partial S/Br substitution in the framework. Bi13S18I2 and Bi13S17Br3 are n-type semiconductors with similar optical bandgaps of ∼0.9 eV but different charge and heat transport properties. Due to the framework S/Br disorder, Bi13S17Br3 exhibits lower thermal and electrical conductivities than the iodine-containing analogue. The high Seebeck coefficients and ultralow thermal conductivities indicate that the reported bismuth sulfohalides are promising platforms to develop novel thermoelectric materials.